For example, in a system with limited resource of a CPU (Central Processing Unit) or a memory, such as an embedded system, in a case of performing a speech recognition process involving an advanced signal processing including a noise suppression process or the like, a situation could occur in which the signal processing will not be within the actual time due to the poor performance of the system itself or a conflict with other processes. If the signal processing, which is a preceding stage process, does not fall within the actual time, delay is generated in the speech recognition process, and thereby resulting to generate a problem such as a delayed response and an overflow of a buffer for speech input.
In regard to such a problem, patent document 1, for example, discloses a method to pass the amount of characteristics to a recognition engine when detecting no sound in the speech recognition process whether or not it is determined to be an end.
Further, patent document 2, for example, discloses a method to suppress the delay by suppressing the number of accesses to an HDD (Hard Disk Drive) in the speech recognition process.
Furthermore, patent document 3, for example, discloses a speech recognition apparatus that evaluates whether it is a speech section or a noise section, creates a speech model from an acoustic characteristic amount of a noise section signal, calculates a speech characteristic amount average from the acoustic characteristic amount of the speech section signal, and obtains a speech recognition result using them.